First-order authentication system

ABSTRACT

A system ( 10 ) is provided for performing first-order authentication of articles marked with indicia ( 30 ) discernible in visible, ultraviolet, or infrared light or tagged with UV- or IR-sensitive chemicals. The first-order authentication system provides reliable visual authentication by providing for juxtaposition of the article-under-test ( 20 ) with a known reference-standard sample-specimen ( 90, 100,  or  300 ), while the article-under-test ( 20 ) is illuminated by a suitable source ( 65  or  250 ) of radiation in the visible, ultraviolet, or infrared portions of the electromagnetic spectrum. Thus, the system ( 10 ) facilitates comparison to differentiate a genuine article from a counterfeit article with first-order accuracy but at a substantially lower cost than that of automated authentication systems. Additionally, the system can be used in both portable and desk top embodiments. The system preferably has optional interchangeable holders ( 140  or  400 ) for various articles-under-test as well as an optional interchangeable, holder ( 115 ) for various reference-standard sample-specimens. Some embodiments utilize structures incorporating split-image optics ( 200 ), superposed-image optics, and/or a blink-comparator.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is related to Provisional patent applicationSer. No. 60/102147 filed in the United States Patent and TrademarkOffice on Sep. 29, 1998.

DESCRIPTION

[0002] 1. Technical Field

[0003] This invention relates to a system that facilitatesauthentication of genuine articles and discrimination of genuinearticles from counterfeit articles. This invention relates moreparticularly to first order authentication, detection, discrimination,and recognition of indicia or taggants that become visible when they areexcited by sources of invisible radiation, such as ultraviolet (UV) orinfrared (IR) light sources. Specifically, the authentication isaccomplished by human judgment through visual means by comparing anarticle with an applicable reference-standard sample-specimen providedwith the apparatus and disposed to facilitate comparison.

[0004] 2. Background Art

[0005] The counterfeiting of articles of many kinds has become a seriousproblem worldwide causing great loss of revenues to legitimate business,individuals, and governments. One of the methods to protect the articlesfrom counterfeiting is incorporation of special markings that aredifficult to reproduce but that enable easy detection. Examples arearticles that are tagged or marked with identification marks that areprinted using normally invisible chemicals, such as UV- or IR-sensitivechemicals. (Throughout this description, the term “taggants” refers tomaterials or visible or invisible indicia included in or on an articleto mark it for authentication. In order to avoid confusion with “pure”ultraviolet light sources that emit only ultraviolet light, thosecommonly available light sources that emit ultraviolet light and alsoemit some visible light will be referred to as “black light” sources.)

[0006] Counterfeiting, moreover, has produced articles with similarhidden identification marks that are so sophisticated that only highperformance scanners and laboratory equipment can distinguish thecounterfeit article from the genuine article. At the same time,counterfeiters using primitive methods, apparatus, and processes haveproduced some less valuable articles, such as food stamps, coupons,toys, etc. that will require first order authentication in the field.Since the articles in question do not command high value, it is oftennot practical to employ sophisticated apparatus in the first orderauthentication process. Instead, low-cost and reasonably reliableapparatus is preferred.

[0007] Many devices have been developed which can automaticallydetermine authenticity of articles by detecting markings made withsubstances that are not normally visible in ordinary light, but becomedetectable by the devices when illuminated with non-visible radiation.U.S. Pat. No. 3,573,472 to Madalo discloses a label verification systemin which each label to be verified is imaged onto a matrix ofphotocells, and an authentic label is imaged onto another matrix ofphotocells. Symbols on the labels preferably contain photoluminescentsubstances, and the matrix of photocells is provided with suitablefilters, so that when the labels are illuminated with ultraviolet light,photocell responses are at a much higher degree of contrast. U.S. Pat.No. 4,146,792 to Stenzel et al. discloses paper secured against forgeryand a device for checking the authenticity of such papers. The papercarries materials that fluoresce in the visible, ultraviolet, orinfrared spectral range in characteristic emission spectra. The deviceincludes a light source for exciting fluorescent substances, a condenserlens concentrating the light emitted by the paper, a narrow bandinterference filter, a focusing lens, and a series of photocellsarranged in the focal plane of the focusing lens. The outputs of thephotocells are fed to a preamplifier and then to a comparator, andoutputs of photocells are compared to establish the authenticity of thepaper. U.S. Pat. No. 4,277,774 to Fujii et al. discloses a currencydiscriminating apparatus that utilizes the presence of a light-emittingsubstance in a printed zone of the currency when irradiated withultraviolet rays. The apparatus comprises an ultraviolet ray-emittingmember, a photoelectric converter element, and a discriminating circuitfor checking pattern signals. U.S. Pat. No. 4,558,224 to Gober disclosesa counterfeit paper currency bill warning device that utilizes thecharacteristic fluorescence of genuine paper currency. In Gober'sdevice, an ultraviolet lamp illuminates the paper currency of unknownorigin, and a sensor circuit responds to fluorescent radiation from thecurrency to give a signal to an indicator which displays an indicationof the fluorescence of the unknown paper currency relative to thefluorescence of genuine paper currency. The sensor is a photoresistorand the indicator is a variable intensity light or a digital display.

[0008] U.S. Pat. Nos. 4,451,521 and 4,598,205 to Kaule et al. disclosesecurity paper with authenticity features in the form of substancesluminescing only in the invisible region of the optical spectrum. Acorresponding test apparatus makes it possible to check the authenticityof the security paper in the presence of customers but unnoticed bythem. The invisibility of the test signal and the authenticity signalare taken advantage of, and the test device is hidden behind a platenon-transmissive for visible light, which however is transmissive forthe test signal and for the authenticity signal. U.S. Pat. No. 4,833,311to Jalon discloses a security marking procedure, an apparatus to sense asecurity marking, and fiduciary documents provided with securitymarkings utilizing rare-earth chelates consisting of at least two rareearths. The fluorescent wavelengths of the rare-earth chelates vary asfunctions of temperature.

[0009] U.S. Pat. No. 4,889,367 to Miller discloses a multi-readableinformation system which includes information in a machine-readable barcode and a different type of information that occupies the same fieldarea of the substrate material, such as information in human-readablesymbology that is printed in at least a portion of the area occupied bythe bar code. The bar code is printed in a first ink that can be readutilizing energy of a first wavelength and the human-readable symbolsare printed in a second ink that can be read under illumination by ahumanly visible wavelength. U.S. Pat. No. 5,414,258 to Liang disclosesapparatus and methods for calibration of fluorescence detectors; theapparatus incorporates standard target elements comprising predeterminedfluorescent substances with known emission spectra and eithernon-fluorescent substances or fluorescent substances with other knownemission spectra.

[0010] Automated authentication systems for articles tagged with UVsensitive chemicals are well established, for example, the AngstromTechnologies Omni series UV scanners and systems. Similar systems aredescribed in U.S. Pat. No. 4,642,526 to Hopkins, in U.S. Pat. Nos.5,418,855, 5,548,106, 5,574,790 and 5,666,417 to Liang et al., and inU.S. Pat. No. 5,719,948 to Liang. These authentication systems prove tobe accurate and fast in authentication without needing any humansubjective judgment. They are commonly employed to differentiatevaluable genuine articles from the counterfeit articles. However, theyare also relatively expensive and sometimes cannot be justified forapplications where the value of the articles in question is very low.Furthermore, in situations where not all articles have been tagged withthe specialty chemicals, such as older passports, bank notes, and somecredit cards, a fully automated system could give false readings if thearticles are scanned automatically without human intervention.Similarly, a universal automated scanner for all credit cards or banknotes will be a challenging task because various credit cards and banknotes have different markings, with different taggants, and at differentlocations on the cards or notes.

[0011] PCT International Publication WO 97/06502 “Optical ImageAuthenticator” by Atherton et al. describes an authentication system inwhich a light intensity pixel array is detected and compared with areference pixel array to determine if each pixel is either good or bad.Authentication is done on the basis of the number of good/bad pixels ortheir ratio.

[0012] Several of the approaches in the prior art have addressed onlyindividual currency standards in existence at the time of theirinvention, such as general broad-band fluorescence from paper stock,commonly known as background fluorescence, emitted by brightener orother substance used in the paper-making process. Any broad-bandfluorescent ink can possibly trigger a detector of these types; forexample, a mark that has fluorescent characteristics positioned anywhereon the currency or a simple stamp mark with fluorescent property.Therefore, such methods are not completely reliable.

[0013] The prior art generally does not describe solutions to theproblem of how to authenticate the recently printed United States ofAmerica currency in which each denomination ($20, $50, $100 and theplanned future $10 and $5 bills) has its own unique fluorescent“security thread.” Currencies of other nations, such as France andSwitzerland, also have unique fluorescent features for each denominationof currency. Furthermore, the prior art does not address the method ofauthenticating other security features in the currency or in otherarticles that have security features other than fluorescent features.

[0014] Typically, desirable modem security features contain both visibleand invisible means for enhanced counterfeit protection. The U.S.currency mentioned above has several security features visible underordinary light characterized by wavelengths in the visible portion ofthe spectrum, in addition to its fluorescent features. For example, ithas fine-line printing patterns in selected areas, a watermark,color-shifting ink in selected indicia, microprinting, Federal ReserveSystem indicia, etc. Many other currencies, such as those of Austria,Egypt, France, Germany, Italy, the Netherlands, and Switzerland, alsohave combinations of invisible and visible features, such as fluorescentpaper, stripes, numerals, or threads, and a watermark visible inordinary visible light. Therefore, it is desirable, under somesituations, to have an authentication system that is more flexible andversatile even if it requires human judgment and even if it is lessaccurate and capable than an automatic system.

[0015] In many applications, it is desirable to have fast authenticationcapability of an article with visual means because the articles are notuniformly tagged for automated scanning such as U.S. currency $100, $50,or $20 bills, or credit cards, such as Visa, Master Charge, or AmericanExpress credit cards.

[0016] The commonly available black lights with some UV output and IRviewing scopes are simple to operate, have great flexibility and are ofrelatively low cost. Authentication of articles in question using onlysuch apparatus is, however, completely dependent on subjective humanjudgment. Since counterfeiters can often imitate the taggant with aroughly similar chemical and printing, including printings by hand andrubber stamp, it will challenge a human examiner's ability todistinguish counterfeit articles from the genuine articles. Therelatively unreliable earlier authentication methods merely using blacklights or IR viewing scopes alone have very limited practical value. Itis therefore desirable to have an improved apparatus and methodssuitable for first-order visual authentication.

DISCLOSURE OF INVENTION

[0017] An overall object of the invention is an authentication systemthat is low in cost and versatile but reliable to the first order.Portability, ease of operation, interchangeability of holders of thearticle to be authenticated (henceforth “article-under-test”), andprovisions for a reference-standard sample-specimen are other objects ofthis invention.

[0018] A system is provided for performing first order authentication ofarticles marked with indicia discernible in visible, ultraviolet, orinfrared light or tagged with UV- or IR- sensitive chemicals. Thefirst-order authentication system provides reliable visualauthentication by providing for juxtaposition of the article-under-testwith a known reference-standard sample-specimen, while thearticle-under-test is illuminated by a suitable source of radiation inthe visible, ultraviolet, or infrared portions of the electromagneticspectrum. Thus, the system facilitates comparison to differentiate agenuine article from a counterfeit article with first-order accuracy butat a substantially lower cost than that of automated authenticationsystems. Additionally, the system can be used in both portable and desktop embodiments. The system preferably has optional interchangeableholders for various articles-under-test as well as an optionalinterchangeable holder for various reference-standard sample-specimens.Some embodiments utilize structures incorporating split-image optics,superposed-image optics, and/or a blink-comparator.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019]FIG. 1 shows a perspective view of a preferred embodiment of anauthentication apparatus made in accordance with the invention.

[0020] FIGS. 2A-2D show perspective views of parts of an alternativeembodiment of authentication apparatus made in accordance with theinvention.

[0021]FIG. 3 shows a perspective view of a third embodiment of anauthentication apparatus made in accordance with the invention.

[0022]FIG. 4 shows a schematic diagram of a fourth embodiment of anauthentication apparatus.

[0023]FIG. 5 shows a perspective view, partially cutaway, of a fifthembodiment of an authentication apparatus.

[0024]FIG. 6 shows a perspective view of an accessory used with anauthentication apparatus.

[0025]FIG. 7 shows a front elevation view of the apparatus of FIG. 5.

[0026]FIG. 8 shows a top plan view of a reference-standardsample-specimen suitable for a specific application.

[0027]FIG. 9 shows a top plan view of an article holder platform.

[0028]FIG. 10 shows a perspective view of an article holder platform.

MODES FOR CARRYING OUT THE INVENTION

[0029] The invention will be made clear by the following more detaileddescription, read in conjunction with the drawings.

[0030]FIG. 1 shows a perspective view of an authentication apparatusmade in accordance with the invention. FIGS. 2A-2D show perspectiveviews of parts of an alternative embodiment. As shown in FIG. 1, anauthentication system 10 according to this invention consists of ahousing 60 containing an excitation source 65, such as a white-lightlamp (visible spectrum range), UV lamp, black light, or IR lamp, areceptor portion 50 for the article-under-test 20, and a holder 115,preferably a movable one, for the reference-standard sample-specimen 90that is used as a reference standard during the authentication process.Reference-standard sample-specimen 90 preferably includes one or morevisible examples of genuine authentication features. The arrows in FIGS.1 and 3 indicate schematically the direction of inserting anarticle-under-test 20. Article-under-test 20 is not shown in FIG. 1, butexamples are shown in FIGS. 2C and 5. Excitation source 65 may becontained within housing 60 as shown, or may be attached to the housing.Receptor portion 50 may be an integral part of housing 60 as shown, ormay be removable from the housing and may be made interchangeable.Reference-standard sample-specimen holder 115 may be stationary ormovable.

[0031] Thus, article-under-test 20 is preferably marked with indicia 30visible under illumination with radiation in a predetermined spectralrange, which may be entirely in the visible range of the spectrum,partly or wholly in the ultraviolet spectral range, or partly or whollyin the infrared spectral range.

[0032] Article-under-test 20 is preferably held in a holder 140 thatfits into receptor portion 50. Authentication system 10 preferably has acover portion 70 with a viewing window 80. Viewing window 80 preferablypasses visible light but blocks the invisible UV or IR radiation fromexcitation source 65. Throughout this description and the appendedclaims, the terms “invisible radiation” or “non-visible radiation” areused to mean radiation characterized by one or more wavelengths in aportion of the electromagnetic spectrum outside the visible spectralrange, such as the ultraviolet or infrared portions of theelectromagnetic spectrum.

[0033] A user who wishes to examine an article-under-test 20 forauthenticity disposes article-under-test 20 in suitable relation toviewing window 80. When the excitation source 65 is turned on, thearticle-under-test is illuminated by the visible-, UV-, or IR-lightsource 65, and a taggant, visible indicia, or fluorescent image indicia30 become visible. The reference-standard sample-specimen 90 isjuxtaposed with the article-under-test 20 by being disposed near thearticle-under-test 20 or superimposed upon the article-under-test 20 orupon a portion of the article-under-test 20. The visible indicia,taggant, or fluorescent image 30 is then compared to thereference-standard sample-specimen 90 for authentication.

[0034] In preferred embodiments of the invention, for the lowest cost,the article-under-test 20 with its optional holder 140 andreference-standard sample-specimen 90 with its optional holder 115 arestationary in use. A slot 130 is provided for accommodating a movablereference-standard sample-specimen 90 and/or its optional holder 115.FIG. 2B shows a holder 115 for a reference-standard sample-specimen,with a salient portion 120 that fits slidably into slot 130.

[0035] In yet another embodiment, holders 115 and/or 140 are madeinterchangeable so that different articles and/or reference-standardsample-specimens can be used in the same basic authentication system 10.In the embodiment illustrated in FIG. 2C and 2D, the article holder is aspecial receptor 140 specifically designed for the particulararticle-under-test 20. The reference-standard sample-specimen 90 iscontained in a movable holder 115 (FIG. 2B) that can be positioned nearor superimposed upon the article-under-test 20 for effective comparison.For a different article-under-test 20, a new holder 140 and a newreference-standard sample-specimen holder 115 are used in place of thepreviously mentioned holders.

[0036] The housing 60 including its base 40 is preferably made oflightweight material such as injection molded ABS plastic for portableapplications and low cost in this preferred embodiment. In anotherembodiment, housing 60 is made of sturdier material, such as metal or adifferent plastic for stability in a desktop application.

[0037] Conventional AC power and/or DC power and suitable switches (150and/or 160) are provided for powering the excitation source 65 in theauthentication system 10.

[0038] The article-under-test 20 or the article holder 140 can actuate amomentary on/off switch 170 controlling the excitation source. Switch170 is shown in FIG. 1. A conventional numeric counter (not shown)with/without reset is wired in series with the momentary switch so thatit can register the number of articles that have been authenticated.Another conventional numeric counter (not shown) can be manuallyactivated to register the number of counterfeit articles that have beendiscovered. Optionally, a conventional output device (not shown) may beconnected to these switches to link the authentication apparatus to aremote or external conventional data acquisition system to recordinstances of genuine and counterfeit articles.

[0039] There are many possible embodiments for the taggants or forindicia 30 marking the article-under-test 20 for authentication. Forexample, a stripe with predetermined length, width, orientation, colorcharacteristics, and intensity can be printed on a specific location ofthe article 20, as shown in FIG. 2B. Reference-standard sample-specimen90 has corresponding fluorescent indicia 110. In a particular method(“missing link” method), an image 30 is printed with special UV- orIR-sensitive chemicals that completes an otherwise incomplete image thatis discernible under visible light. Only the combination of the normallyvisible and the normally invisible parts is readily recognizable. This“missing link” method is described in U.S. Pat. Nos. 5,719,948 and5,867,586, of which the entire disclosure of each is hereby incorporatedby reference. Thus, it will be appreciated that the present inventionfacilitates visual verification of many kinds of authenticationfeatures: those features discernible in ordinary light in the visiblespectrum, those visible only when illuminated by invisible light outsidethe visible spectrum, and combinations of both visible and invisiblefeatures.

[0040] In another (additional or alternative) method, a sample specimen100 that is printed on a transparent film is used, and is superimposedover the article-under-test 20 to improve the accuracy of theauthentication process. Furthermore, this apparatus can be used toauthenticate visible indicia or combinations of both visible andinvisible indicia. This apparatus can also be employed to determine ifso-called “tamper-evident” seals have been compromised. In the latterapplication, a suitable un-tampered seal is depicted in thereference-standard sample-specimen. Many other methods can be employedwith this authentication system to improve the reliability of detectingcounterfeit or tampered-with articles.

[0041] For articles that are tagged with infrared-sensitive chemicals,the excitation source 65 is an IR lamp and the viewing window isreplaced or augmented with an appropriate optical filter or filters sothat the taggant or fluorescent image is visible. The viewing window mayinclude one or more infrared (IR) bandpass filters, limiting the rangeof wavelengths of IR radiation.

[0042]FIG. 3 shows an embodiment having an infrared viewer 175, for usewith taggants visible only when viewed in the infrared portion of thespectrum. Infrared viewer 175 may be a conventional infrared viewer or“IR scope,” such as the models 31074, 37826, or 38173 available fromEdmund Scientific Company, Inc. (Edmund Industrial Optics Division) ofBarrington, N.J., or the models NZT-1 or NV-100 available from OrionTelescopes and Binoculars of Santa Cruz, Calif. A person of ordinaryskill in this field will recognize that such conventional infraredviewers are conventionally designed for relatively long-distance viewingand that their use in the present invention may require adaptation withsuitable infrared optics for focusing at short distances (e.g., aninfrared-transparent close-up or “macro” lens, such as the model 38175close-up attachment available from Edmund Scientific Company, Inc.,Edmund Industrial Optics Division, of Barrington, N.J.). Equivalentreflective optics may be used in place of an infrared-transparentclose-up or “macro” lens. Some conventional infrared viewers, such asthe model NV-100 mentioned above, include a built-in infrared lightsource. Using such a viewer in the present invention allows substitutionof the built-in IR source for the distinct source 65 shown in FIGS. 1and 3. In the embodiment of FIG. 3, the top surface of the apparatus maybe opaque to visible light as depicted in FIG. 3, but transparent to theinvisible infrared light. A viewing window 80 as shown in FIGS. 1 and 2Ashould have suitable transmission characteristics for the wavelengths ofvisible and/or invisible light to be transmitted.

[0043] With either UV or IR excitation sources, the source 65 may beoptionally modulated at a frequency (e.g. 5 Hz) and duty cycle (e.g.50%) that is easily perceptible to the human user. If the excitationsource is not modulated at such a frequency, it may remain continuouslyactivated for ease of operation; or else, it may be activated only ondemand to conserve energy. As mentioned above, “on-demand” activation ofsource 65 may be accomplished by a “momentary” on/off switch 170actuated by insertion of an article-under-test 20 to be authenticated orby article holder 140.

[0044]FIG. 4 shows schematically another embodiment of the invention, inwhich optical means 200, such as a mirror, half-silvered mirror, prism,or beam splitter, provides a “spilt-field” or “split-image” view throughwindow 80. In this embodiment, the optics can be arranged optionally sothat a user sees a single split image of an article, with one half ofthe image corresponding to the article-under-test 20 and the other halfcorresponding to the reference-standard sample-specimen 90. In a similarembodiment, the optics 200 are arranged to superpose an image of thereference-standard sample-specimen 90 over the article-under-test 20 orover its image. As in other embodiments, the reference-standardsample-specimen 90 is disposed on the reference-sample specimen holder.The image of the reference-standard sample-specimen is superposed in atleast partial alignment with the article-under-test 20 or with itsimage. The schematic representation in FIG. 4 is intended to portrayeither split-image or superposed-image arrangements. Such embodimentsallow precise alignment of the article-under-test 20 with thereference-standard sample-specimen 90 and more exact visual comparisonsof the characteristics such as the position(s) and color(s) of indicia110 with corresponding features represented on reference-standardsample-specimen 90.

[0045]FIGS. 5 and 7 respectively show a perspective view and a frontelevation view of a fifth embodiment 200 of the apparatus, having ahousing base 210, the top surface 140 of which optionally supports aviewing window (shown partially cutaway in FIG. 5). Top surface 140 hasa slot 215 for accommodating a movable part 290 (FIG. 6, describedbelow). A receptor space 220 (Cf. FIG. 7) is provided for receivingarticle-under-test 20, which, if authentic, has authentication indicia30. An arrow in FIG. 5 represents insertion of article-under-test 20into receptor space 220. This embodiment has both a source 65 ofnon-visible radiation and a source 250 of bright visible light forcomparison of watermarks etc. in article 20 with corresponding featuresdepicted in a reference-standard sample-specimen 90. Visible source 250is in a recess 240 (preferably with reflective inner walls 280) underthe receptor space 220. Non-visible source 65 is in a recess 230,preferably with reflective inner walls, also disposed under receptorspace 220. Optional optical elements 260 and 270 fit in relativelyshallow recesses at the top of recesses 230 and 240 respectively toprovide optical filters. Optical elements 260 and 270, if used, havetransmission characteristics suitable for the non-visible or visibleradiation of the respective sources 65 or 250. Alternatively (or incombination with optical filtering), optical elements 260 and/or 270 mayincorporate a reference-standard sample-specimen 90. For clarity,optical elements 260 and 270 are omitted from FIG. 5, but shown in FIG.7. FIG. 7 also shows an internal battery compartment 285 for containinga conventional battery power supply and suitable connections when theapparatus is used in its portable configuration.

[0046] As mentioned above, a reference sample specimen 100 may beprinted on a transparent substrate and superimposed over thearticle-under-test 20. Such a transparent type of reference samplespecimen 100 may be included in a viewing window, or alternatively maybe carried on a movable part 290. In a variation of the embodiment ofFIGS. 5 and 7, optical elements 260 and 270 may be replaced withindividual reference-standard sample-specimens of the transparent type100, suitable for different portions of article-under-test 20. In eachcase, the apparatus provides for disposing a reference-standardsample-specimen 90 or 100 for juxtaposition with the article-under-test20 for comparison during authentication.

[0047]FIG. 6 shows a perspective view of a movable part 290 used withthe apparatus embodiment of FIG. 5. Movable part 290 fits a slot in base40 of housing 60 and is movable for examining various portions ofarticle-under-test 20 disposed in receptor 220 of the apparatus forjuxtaposition with a reference-standard sample-specimen 90. For someapplications, movable part 290 itself carries reference-standardsample-specimen 90 for juxtaposition over article-under-test 20. Movablepart 290 may include a magnifying glass, e.g., a Fresnel lens, and/ormay include an optical filter.

[0048]FIG. 8 shows a top plan view of a reference-standardsample-specimen 300 suitable for a specific application. Thisreference-standard sample-specimen has a reference line 340 for precisepositioning of an edge of a currency bill, and three visible lines 310(green), 320 (red), and 330 (yellow). The colors of lines 310, 320, and330 respectively match the colors of visible fluorescence from plastic“security threads” embedded in the paper of authentic United Statescurrency bills of $20, $100, and $50 denominations excited by suitableultraviolet radiation. The positions of these colored lines 310, 320,and 330 also respectively match the correct positions of thecorresponding plastic security threads embedded in the paper ofauthentic United States currency bills of $20, $100, and $50denominations. Thus, the reference-standard sample-specimen 90 shown inFIG. 8 includes visible examples of genuine authentication features ofauthentic United States currency bills. FIG. 8 is not drawn to the exactscale of U.S. currency bills, but an actual reference-standardsample-specimen 300 is made to the correct scale, to provide for precisejuxtaposition with the currency article-under-test 20. If and whensimilar security features are incorporated into bills of otherdenominations, reference-standard sample-specimens 300 are madeaccordingly. Such reference-standard sample-specimens are made withcolors and positions of the particular security features incorporatedinto those bills of other denominations, and are preferably added to thefeatures shown in FIG. 8 so that a single reference-standardsample-specimen can cover all bill denominations. Similarly,reference-standard sample-specimens corresponding to the securityfeatures incorporated into currency of other countries provide forauthentication of those currencies.

[0049]FIGS. 9 and 10 respectively show a top plan view and a perspectiveview of an article holder platform 400 having a salient portion 410 thatfits into a mating slot 75 in housing 60 of authentication apparatus 10.Article holder platform 400 has a reference line 340, corresponding toreference line 340 of the reference-standard sample-specimen 300 of FIG.8. The reference line 340 of FIGS. 9 and 10 is preferably formed as aphysical ridge or step in the surface, to facilitate alignment of anarticle-under-test 20 by positioning the edge of article 20 against theridge or step.

[0050] Thus, one important aspect of the invention is an apparatus forauthenticating an article, the apparatus including a housing, a receptorwithin the housing for receiving and supporting the article-under-testduring authentication, and a removable reference-standardsample-specimen disposed for juxtaposition with the article-under-testfor comparison with the article-under-test during authentication. A usercan see both the article-under-test and the reference-standardsample-specimen simultaneously and juxtaposed for easy comparison, andcan easily compare particular authentication features directly withrespect to multiple characteristics such as size, position, orientation,contrast, and color (e.g., hue, color saturation, and brightness). Inother important aspects of the invention, in which the article (ifauthentic) has been previously marked with indicia for authentication,the apparatus has a source of radiation disposed within its housing, andthere is a receptor within the housing for receiving thearticle-under-test and supporting the article-under-test in a positionsuch that the indicia are illuminated by the radiation duringauthentication. A particularly useful aspect of the invention exploitsauthentication indicia visible only under illumination with invisibleradiation, and the source of radiation includes at least a source ofinvisible radiation, such as ultraviolet or infrared radiation.Optionally, the apparatus can have a switch, such as a pushbutton switchto activate an audible and/or visible alarm in case of detection of acounterfeit article, and optionally, such an alarm may be locatedremotely from the authentication apparatus.

INDUSTRIAL APPLICABILITY

[0051] The invention may be used for first-order authentication ofarticles in many applications where the complexity and expense ofautomatic authentication is not easily justified or is logisticallyunsuitable or inconvenient to employ, such as in the authentication oftheatre tickets, promotional premiums such as prize coupons, toys, andin mobile field applications or in a brightly-lighted environment. Yetanother application example is the detection of articles or packageseals that have been tampered with. The description of the embodimentsof the present invention is given above for the understanding of thepresent invention. It will be understood that the invention is notlimited to the particular embodiments described herein, but is capableof various modifications, rearrangements, and substitutions that willnow become apparent to those skilled in the art, without departing fromthe scope of the invention. Functionally equivalent elements andmaterials may be substituted for those used in the embodiments as shownherein. For example, it will be recognized that there are manyfunctionally equivalent means for presenting a split field or splitimage to the user, as is done in some conventional camera rangefindersor conventional optical comparators. The reference-standardsample-specimen may include or may consist of a printed description offeatures to be authenticated and/or the salient characteristics of thosefeatures, or it may include printed instructions describing how todetermine authenticity of an article-under-test. In addition, theoptical arrangement or excitation source switching can be varied toutilize the methods of conventional “blink comparators” wherein thefeature of interest is made to blink on and off to ensure the user'sattention.

[0052] Therefore it is intended that the following claims cover all suchmodifications and changes as fall within the true spirit and scope ofthe invention.

What is claimed is:
 1. An apparatus for authentication of an article,comprising: a) a housing, b) a receptor within said housing forreceiving and supporting said article during authentication, and c) aremovable reference-standard sample-specimen disposed for juxtapositionwith said article for comparison during authentication.
 2. An apparatusfor authentication of articles marked with indicia, comprising: a) ahousing, b) a source of radiation disposed within said housing, c) areceptor within said housing for receiving said article and forsupporting said article in a position to be illuminated by saidradiation during authentication, and d) a removable reference-standardsample-specimen disposed for juxtaposition with said article forcomparison with said indicia on said article during authentication. 3.An authentication system as in claim 2 , wherein said source ofradiation is contained in said housing.
 4. An authentication system asin claim 2 , wherein said source of radiation is attached to saidhousing.
 5. An authentication system as in claim 2 , wherein saidreceptor is an integral part of said housing.
 6. An authenticationsystem as in claim 2 , wherein said receptor is removable from saidhousing.
 7. An authentication system as in claim 2 , wherein saidreceptor is interchangeable.
 8. An authentication system as in claim 2 ,wherein said receptor has a size and shape adapted for accommodatingvarious articles of a predetermined set of articles.
 9. Anauthentication system as in claim 2 , wherein said receptor has a sizeand shape uniquely designed for a specific article.
 10. An apparatus asrecited in claim 2 , wherein said indicia are visible under illuminationwith visible-spectrum radiation, and said source of radiation comprisesa source of said visible-spectrum radiation.
 11. An apparatus as recitedin claim 2 , wherein said indicia are visible only under illuminationwith invisible radiation, and said source of radiation comprises asource of said invisible radiation.
 12. An authentication system as inclaim 11 , wherein said source of said invisible radiation is a sourceof ultraviolet light.
 13. An authentication system as in claim 12 ,wherein said source of ultraviolet light is a black light lamp.
 14. Anauthentication system as in claim 11 , wherein said source of saidinvisible radiation is a source of infrared light.
 15. An apparatus forauthentication of articles marked with indicia visible underillumination with radiation in a predetermined spectral range, saidapparatus comprising: a) a housing, b) a source of said radiationdisposed within said housing, c) a receptor within said housing forreceiving said article and for supporting said article in a position tobe illuminated by said radiation during authentication, and d) means forcomparing said article with a reference standard.
 16. An authenticationsystem as in claim 15 , wherein said source emits radiation at leastpartially in the visible portion of the electromagnetic spectrum.
 17. Anauthentication system as in claim 15 , wherein said source emitsradiation at least partially in the ultraviolet portion of theelectromagnetic spectrum.
 18. An authentication system as in claim 15 ,wherein said source emits radiation at least partially in the infraredportion of the electromagnetic spectrum.
 19. An authentication system asin claim 15 , wherein said means for comparing said article with areference standard includes a reference-standard sample-specimen holder.20. An authentication system as in claim 19 , wherein saidreference-standard sample-specimen holder is part of said housing. 21.An authentication system as in claim 19 , wherein saidreference-standard sample-specimen holder is removable from the housing.22. An authentication system as in claim 19 , wherein saidreference-standard sample-specimen holder is interchangeable.
 23. Anauthentication system as in claim 19 , wherein said reference-standardsample-specimen holder is adapted for accommodating various samples. 24.An authentication system as in claim 19 , wherein saidreference-standard sample-specimen holder is uniquely designed for aspecific sample.
 25. An authentication system as in claim 19 , whereinsaid reference-standard sample-specimen holder is stationary.
 26. Anauthentication system as in claim 19 , wherein said reference-standardsample-specimen holder is movable.
 27. An authentication system as inclaim 19 , wherein said reference-standard sample-specimen holder holdsa transparent sample specimen for superimposing said sample specimenover said article.
 28. An authentication system as in claim 15 , whereinsaid means for comparing said article with a reference standard includesa viewing window.
 29. An authentication system as in claim 28 , whereinsaid viewing window comprises an opening.
 30. An authentication systemas in claim 28 , wherein said viewing window comprises an opticalfilter.
 31. An authentication system as in claim 28 , wherein saidviewing window includes a magnifying glass.
 32. An authentication systemas in claim 28 , wherein said viewing window includes one or moreinfrared (IR) bandpass filters.
 33. An authentication system as in claim28 , wherein said viewing window comprises an infrared (IR) viewer. 34.An authentication system for distinguishing a genuine article from acounterfeit article, said authentication system comprising a housing, anexcitation source capable of emitting radiation in a predeterminedportion of the electromagnetic spectrum, an article receptor disposed tohold an article for illumination by said excitation source, and areference-sample specimen holder disposed in juxtaposition with saidarticle receptor.
 35. An authentication system as recited in claim 34 ,further comprising a reference-sample specimen disposed on saidreference-sample specimen holder for comparison with said article. 36.An authentication system as recited in claim 35 , wherein saidreference-sample specimen comprises one or more visible examples ofgenuine authentication features.
 37. An authentication system as inclaim 35 , further comprising optical means for displaying a split imagecomprising a first image portion of said article and a second imageportion of a reference-sample specimen disposed on said reference-samplespecimen holder.
 38. An authentication system as in claim 37 , whereinsaid means for displaying a split image comprises a mirror.
 39. Anauthentication system as in claim 37 , wherein said optical means fordisplaying a split image comprises a half-silvered mirror.
 40. Anauthentication system as in claim 37 , wherein said optical means fordisplaying a split image comprises a prism.
 41. An authentication systemas in claim 37 , wherein said optical means for displaying a split imagecomprises a beam splitter.
 42. An authentication system as in claim 32 ,wherein said excitation source of said radiation is modulated.
 43. Anauthentication system as in claim 42 , wherein said excitation source ofsaid radiation is modulated at a frequency and duty cycle perceptible toa human viewer.
 44. An authentication system as in claim 34 , furthercomprising optical means for superposing upon said article and in atleast partial alignment with said article, an image of areference-sample specimen disposed on said reference-sample specimenholder.
 45. An authentication system as in claim 34 , wherein saidauthentication system is portable.